本研究之目的，在探索臺灣的上市公司於現金增資後，其長期營業績的變化，並分析其與自由現金流量假說之關係。依據現金增資後一至三年的相關營業報酬數據，與增資前比較，經使用成對資料之T檢定及回歸分析 ，結果發現：一、現金增資後三年內，營業報酬率顯著下降，第一年平圾下降1.37%，第二年減少2.23%，第三年減少2.75%，有逐年擴大的趨勢：二、現金增資前後績效差異之大小，與其增資前之自由現金流量顯著相關，而與負債大小、資訊不稱程度、投資活動、或公司規模等關係不大。本研之結支持自由現金流量假說，對臺灣的企業而言，現金增資之長期績符合自由現金流量假說的解釋。

The purpose of this study is to explore the effect on long term operating performance from seasoned equity offering (SEO), and to test the validity of the free cash flow hypothesis. Using the pairwise T-test and the regression analysis, we find that: (1)the operation performance is declining significantly form one to three years after SEO by 1.37%, 2.23% and 2.75% respectively; (2)the declines in operating performance are highly related with the free cash flow before the SEO. The conclusions of this paper strongly support Jensen’s Free Cash Flow hypothesis. In Taiwan, the long term performance of SEO can be explained by the free cash flow hypothesis.